In barns or buildings for cattle, pigs and other animals and poultry, and oftentimes in industrial type buildings, the lack of heat is usually not a problem. If the building is reasonably well sealed and insulated, heat given off by the animals is adequate to maintain comfortable temperatures.
Freshness of air in such a building is definitely a problem. The air in the pens and stalls becomes foul, acrid and generally spent unless it is frequently changed.
In the past, discharge of spent air was accompanied with loss of heat, and oftentimes the air in many parts of the barn remained foul for lack of adequate air circulation.
Some use of heat exchangers has been made, but buildup of frost and dust has severly limited the use of such heat exchangers.